The present invention relates to antennas installed on vehicles, and more particularly to a vehicle antenna connector having an adaptor capable of electrically connecting with both the UHF attachment base and the NMO attachment base.
Vehicle mounted antenna is usually designed to comprise two major parts, including an attachment base fastened on a vehicle and an antenna element coupling with the attachment base by means of a connector provided at the base portion of the antenna element.
It is well known that there are two major vehicle antenna systems established in today's radio antenna market. The essential different of the two vehicle antenna systems are the distinct configuration of their attachment bases, namely UHF attachment base and NMO attachment base.
FIG. 1 indicates a UHF attachment base 10 which comprises a cylindrical coupling head 11 vertically fastened to the central portion of a base 12. A male screw 111 is formed on the outer circumferential surface of the exposed upper portion of the coupling head 11 and the coupling head 11 has a central conductive hole 13. An antenna 14 having a specific type of antenna connector 15 provided at its base portion must be incorporated with the UHF attachment base 10 for electrically connecting the antenna 14 with the UHF attachment base 10 in order to secure good workability. Such specific antenna connector 15 is specially designed to match the cylindrical coupling head 11 and its central conductive hole 13, which comprises a coupling member 151 having a hollow core chamber 152 to receive the protruded coupling head 11. A female screw 153 is formed on the inside circumferential surface of the coupling member 15 for engaging with the male screw 111 of the coupling head 11. A conductive rod 16 having a diameter fitting the conductive hole 13 of the coupling head 11 is protruded from the center of the bottom of the coupling member 151 and extended to the core chamber 152 adapted to insert into the conductive hole 13 of the coupling head 11 for conductive connection.
FIG. 2 illustrates an NMO attachment base 20 which comprises a coupling platform 21 provided on the central portion of a seat 22. A male screw 211 is formed on the outer circumferential surface of the coupling platform 21. On the central portion of the coupling platform 21 protrudes a central conductive head 23. An antenna 24 having a specific type of antenna connector 25 provided at its base portion must be incorporated with the NMO attachment base 20 for electrically connecting the antenna 24 with the NMO attachment base 20 in order to secure good workability. Such specific antenna connector 25 is specially designed to match the coupling platform 21 and its central conductive head 23, which comprises a coupling sleeve 251 having a female screw 252 formed on its inside circumferential surface so that the coupling sleeve 251 is capable of engaging with the male screw 211 of the coupling platform 21. A short rigid conductive pin 26 is protruded from the center of the bottom surface of the coupling sleeve 251 adapted to keep firmly in contact with the conductive head 23 of the coupling platform 21 for conductive connection.
As described above, the above two structures produces the same effects but has the following shortcomings. The UHF antenna 14 is unable to fit the NMO attachment base 20 and, in opposite, the NMO antenna 24 does not match with the UHF attachment base 10. Both the UHF antenna 14 and the NMO antenna 24 are the unique structures for coupling connecting with the UHF attachment base 10 and the NMO attachment base 20 respectively. Accordingly, it causes unnecessary trouble in stock management and shipment to the manufacturers as well as the retailers. To the user, once the antenna is broken, he or she has to purchase the exact UHF or NMO type of antenna for replacement. Moreover, according to features of the conventional vehicle antenna device, no matter if it is the UHF or NMO antenna system, good conduction contact can only be achieved by very accurate constructive dimension. If the conductive rod 16 of the UHF antenna 14 or the conductive pin 26 of the NMO antenna 24 is merely slightly short, it will unable be in touch, i.e. in conductive contact, with the attachment base. However, if the conductive rod 16 of the UHF antenna 14 or the conductive pin 26 of the NMO antenna 24 is too long the antenna connector 15 or 25 is unable to firmly connected with the attachment base.